Sleep, what is it good for?

The Encyclopedia Brittanica describes sleep as being a recurrent state of reduced physical responsiveness but with periods of high level brain activity. This sleep pattern of behavior is most pronounced among higher order vertebrates. Why this is so, what does it mean, and for what good do we sleep is left unknown. Reviewing recent research provides some answers, but still leaves us restlessly wanting.

A recent paper from the Nedergaard lab, Xie, et al. (2013), and reported in the New York Times raises the possibility that sleep cleans up the metabolic wastes that accumulate in the brain.  Neglecting sleep too much leads to a build up of metabolic wastes such as beta-amyloids, which are tellingly also in increased levels in Alzheimer's and dementia patients.  Severe sleep deprivation might thus lead to temporary - or perhaps even permanent - brain dysfunction and dementia-like symptoms.    The answer here is to sleep for a healthier waking.

Research at the Wilson lab raises the possibility that sleep leads to dreaming which helps consolidate memory formation. Monitoring the neural spiking rates and regions of awake mice running through a particular maze generates a specific pattern of spiking behavior.  When the mice sleep with the monitors still attached, these patterns of spiking can still be detected albeit at sped up or slowed down rates.  This implies the mice are dreaming about the maze they ran through earlier and are either memorizing or otherwise practicing the maze paths in the safety of their sleep. The answer here is to sleep for practice simulations for a better waking.

Klahr and Wallace (1976) raised the possibility that sleep allows the brain to detect and consolidate redundant memories into singletons.  Using their production systems model of using computer-simulation to model cognitive development.  One of their production systems requirements is that similar or redundant events need to be compressed.  E.g. eating a vanilla ice cream cone should only be a novel experience the first time.  Eating it 10 times should not trigger 10 completely separate memories.  Likewise, eating a vanilla frozen yogurt cone should not trigger a completely separate memory.  There should be similarities and significant overlap.  From a computerized perspective, this conserves physical memory space as per rules of entropy.  From a cognitive perspective, eating a vanilla ice cream cone should trigger associative memory recall as in, "Hey, I had this or something very similar before," instead of, "This is catalogued under ice cream cone file with unique ID 62478…" They proposed that this form of generalization learning occurs when the brain has some spare time with sleep and relaxation. The answer here is to sleep for a smarter waking.

Clearly the research seeks to answer what occurs during sleep that assists and supports what happens during the day.  The investigations and analyses can only answer that which is framed in the hypothesis-question.  The hypothesis-question is invariably biased by our perspectives that wakefullness is the main event, or in corporate-busniess speak, the core competency profit center.  Sleep would thus be a cost center, a time and resource drain that attempts to support and service the core competency. Cost centers are last on the budget priority queue and first to be outsourced when the opportunity arises.  So it is with sleep - least important, first to be cut. The above research clearly biases in favor of cutting, reducing, and replacing "relaxed, downtime, [wasteful]" sleep with more efficient means of effecting its benefits. 

What if this perspective were not the only valid one?  What if this perspective were wrong? If War and Peace really were originally called Peace What is it Good For to paraphrase a Seinfeld comedy, would peace simply be the absence of war, a non-interactive period in support of surrounding wars?  As we reject that notion, so should we reject that sleep is merely a non-interactive intermission between the waking acts, but rather a stand-alone active phase in itself. 

How can we investigate sleep with sleep as a primary important function in and of itself? How can we proceed to reverse the ordinary and to ask the extraordinary, to push the boundaries of creativity, and to regard a state in which we all have daily experience but no ability to narrate and share. Perhaps with no narrative capability, we cannot consciously access the autobiographical per Katherine Nelson's work.  We would necessarily be like babies trying to explain what they do. Perhaps this is truly pioneering exploration - to confront that which may be topically mundane but is in truth so far from everyday capture for elucidation that it is a great mystery at our very own doorsteps - or beds, as it were. Just because we cannot explain it does not mean it is not important and cannot be a leading activity.

What if sleep were the creative, strategic planning phase and wake were the manufacturing phase? There is a reason that today's developed economies value creative strategists and analysts with relatively high compensation.